Photocatalysis removing of NO based on modified carbon nitride: The effect of celestite mineral particles

Atmospheric NO is one of the toxic and hazardous gases. Its' levels are continually rising in recent years. As we known, mineral particles contained in the atmosphere may affect the photocatalytic NO removal process. In this study, we found that celestite modification could greatly improve the activity (about 3.8 times) and stability of g-C3N4 for the photocatalytic NO removal. In our system, celestite particles embed in the N vacancies of g-C3N4. The synergistic effect of celestite and N vacancy is the origin of improved NO removal activity. During the light irradiation, photogenerated electrons can be captured and confined by N vacancy. Meanwhile, celestite can transfer these confined electrons to O-2 and produce more OH, which could oxidize NO to nitrate. These findings can help us to understand the influence of mineral particles in the photocatalytic NO removal and design highly efficient NO removal phtocatalysts.